Just in case anyone else runs across this issue, and already has <key>RunAtLoad</key><true/> in their plist, I want to provide some additional solutions.
Double check permissions to make sure that your script is executable (look for an ‘x’):
ls -l /opt/apache-tomcat-5.5.27/bin/startup.sh
Modify permissions if necessary:
chmod +x /opt/apache-tomcat-5.5.27/bin/startup.sh
Also run the script directly first and make sure it works:
/opt/apache-tomcat-5.5.27/bin/startup.sh
If the script is executable, and runs fine directly, try tailing the system log to debug launchd:
sudo launchctl log level debug
tail -f /var/log/system.log
The -f flag (basically) continually shows the end (latest entries) of the log. You can remove this flag to just print a snapshot of the end of the log. If you use this flag, you’ll need to open a new terminal to run other commands. Press CTRL + C to end the tail session. For more information:
man tail
When you’re finished debugging:
sudo launchctl log level error
There are other log levels. For more information:
man launchctl
If you make any changes to the script or plist, make sure you reload the plist. For example:
launchctl unload ~/Library/LaunchAgents/com.tomcat.plist
launchctl load ~/Library/LaunchAgents/com.tomcat.plist
If you ONLY made changes to the script and NOT the plist, you can just restart the plist:
launchctl stop com.tomcat.plist
launchctl start com.tomcat.plist
If you add the following key-value to your plist:
<key>KeepAlive</key>
<true/>
Then you can just run:
launchctl stop com.tomcat.plist
And it will restart automatically.
If none of this helps, and you’re specifically having problems with setting up Tomcat on OS X, this tutorial might be of help.